Sintering Evolving Mn2O3–LaMnO3 Perovskite Heterointerfaces as Highly Active and Durable Catalysts for Catalytic Removal of Volatile Organic Compounds

Abstract

Improving the catalyst performance for the thermal oxidation reaction faces the daunting challenge of the activity–stability trade-off. Herein, an evolved heterointerface was constructed on spherical Mn₂O₃ nanocatalysts to achieve exceptional stability while maintaining adequate activity by simply introducing La. The generation of the active Mn₃O₄–Mn₂O₃ heterointerfaces by La doping was experimentally observed, which further segregates to the surface during thermal aging and forms epitaxially grown heterostructured LaMnO₃–Mn₂O₃ with Mn atoms. The former can act as highly active sites for the deep oxidation of VOCs due to the richness in oxygen vacancies and Mn⁴⁺ ions, while the latter acts as the diffusion barrier to inhibit grain growth and produce advantageous reactive electronic structures around the interface. The La-modified Mn₂O₃ oxide reached 90% conversion in toluene oxidation at 286 °C under the high WHSV of 240,000 mL g^–1 h^–1 and slightly increased to 327 °C after thermal aging at 800 °C. This work provides a versatile strategy for fabricating effective oxidation catalysts with high low-temperature activity and antisintering properties for industrial applications.